Conference Agenda

Even though process simulation for 3D printing has progressed substantially over the past decade and across multiple length-scales, the major issue is about how to link these simulations and then perhaps to combine these models with topology optimization for getting an improved design under the umbrella holistic computational design. The solution is multi-scaling laws which are; homogenization, material multi-scaling and process multi-scaling. The first two multi-scaling techniques allow for extracting macroscopic properties of an entire part based on the data generated by process simulations at lower dimensions, namely micro- and deposition-scale models while process multi-scaling methods enable fast computation of a real-size sample and such models can be improved by involving material multi-scaling . Finally, this holistic model can be incorporated into the topology optimization calculations for a far better design of a part with ultimately no sign of process-induced defects, under the flag of physics-aware topology optimization.

Laser Metal Deposition (LMD) is an additive manufacturing process that utilizes a focused laser beam to melt and deposit powder onto a substrate, enabling the layer-by-layer creation of complex geometries. This study investigates dynamic beam shaping to enhance resource efficiency in LMD, particularly when processing intricate geometries. While conventional Top-Hat and defocused Top-Hat profiles are commonly used, adjusting the laser intensity distribution can improve process quality, especially when dealing with small powder and laser spot diameters. A modified laser intensity distribution alters the melt pool dynamics, thereby influencing the powder utilization rate. A measurement setup is employed to determine the focal position and diameter of the powder stream, allowing for the selection of appropriate boundary geometries for the beam profile. Dynamic beam shapes are then applied coaxially through the powder nozzle. This novel approach results in improved powder utilization rates compared to traditional Top-Hat profiles.

Pure copper exhibits excellent antimicrobial properties, and the pure copper coating on surface such as doorknobs or handrails can effectively prevent the spread of infections. We have developed a high-quality pure copper coating with blue diode lasers for an efficient copper processing method, and employing multibeam laser metal deposition to create a thin layer with a thickness of around 100 µm and the high adhesive strength. However, the circular beam with a spot diameter of 233 µm, much smaller than the powder flow diameter, was previously used, resulting in low layer formation efficiency. To address this, a rectangular beam with a spot size of 584.7 µm×1059 µm was introduced. As a result, a pure copper coating with a thickness of 122.2 µm and a surface roughness of 6.16 µm was formed. Compared to the same quality coating using a circular beam, the layer formation efficiency increased by 3.22 times.

This study investigates the application of a novel deformable mirror system for beam shaping in laser-based welding and directed energy deposition, emphasizing process improvements and robustness. In directed energy deposition, the effects of three near-elliptical Gaussian beam shapes on melt pool and bead geometries were analyzed. The beam shape with the major axis aligned to the wire feeding direction, featuring the highest average power density and intermediate peak power density, provided reduced bead geometry variation and enhanced process stability. For butt joint welding, the system was used to elongate the focused laser beam into elliptical shapes. This approach reduced the sensitivity of the fused zone’s dimensions to joint gaps, minimized the heat-affected zone, and decreased undercuts. The findings demonstrate the potential of beam shaping to enhance robustness, reduce defects, improve energy utilization, and boost productivity in high-power laser processing applications.

This study investigates the application of Optical Coherence Tomography (OCT) for real-time monitoring of the 3D-EHLA (3D-Extreme High Speed Laser Metal Deposition) process. The OCT enables precise measurement of layer thickness and immediate detection of process deviations. The results confirm the capability of OCT to consistently monitor the layer heights at deposition speeds up to 200 m/min. While this project focuses on monitoring, the findings suggest that OCT can also be reliably used for feedback control in future implementations. This integration enhances the reliability of the 3D-EHLA process and supports its implementation in industrial environments. The use of OCT provides a robust solution for addressing the challenges of high-speed additive manufacturing, ensuring product integrity and process efficiency.